Name change from Simon to Peter indicates the apostle being called to a special role of leadership (Abram changed to Abraham - Jacob to Israel - Saul to Paul)
Rock has special significance. It was a Semitic expression designating a solid foundation on which a community would be built (Abraham considered rock as father of the Jewish people)
No one except God was called specifically "rock" and was only used for God
Argument about the Greek use of the word rock - the understanding in Aramaic
MEANS, M: small moveable rocks
NOT! F: Large Rock
MEANS, BOTH: small moveable rocks & Large Rock
In Aramaic NO ARTICLE declaring it masculine or feminine
2. The "gates of hell" is another Semitic expression - the heaviest forces were positioned at the gates so this phrase captures the great war making power of a nation
St. Peter becomes that visible force for the Church Keeping back the power of hell
3. "I will entrust to you the keys of the kingdom of heaven," the number two person held the keys in the OT (Isaiah 22:19-22) This person represented the king acted with his authority, and had to act in accord with the king's mind. St. Peter and his successors represent the Lord on earth
4. Binding things. A rabbi could bind, forbid an act, excommunicate a person for serious sin. And he can loose, declare an act permissible, or reconcile a sinner with the community. St. Peter is given that responsibility.
Teaching authority was given because Jesus would not be with us forever. Through the Bishops of the church, we are able to trace this "laying on of hands" in an unbroken line back to the apostles
The mission that Jesus gave the 12 disciples was to teach others all that He had commanded them. Christ gave them the duty to instruct, preach, teach, and sanctify.